Tobacco pipe



July 13, 1943. K. F. J. KIRSTEN TOBACCO PIPE Filed Aggy 6, 1 940INVENTOR.

Kari fi'J uzsfen W MW ATTORNEY.

Patented July 13, 1943 UNITED STATES PATENT OFFICE TOBACCO PIPE Kurt F.J. Kirsten, Seattle, Wash.

Application May 6, 1940, Serial No. 333,475

2 Claims.

This invention relates to tobacco pipes and is a continuation-in-part ofmy parent application for Letters Patent of the United States filedAugust 30, 1938, Ser. No. 227,483, said pipe, describing the same inmore particularity, being one in which the tobacco-receiving bowl ismounted on a metallic barrel, the barrel having a through-bore intowhich the products of combustion are fed from the bowl. A plug-valve andthe usual mouth-piece serve as closure elements for the two ends of thebore. In addition to this closing function, the plug-valve by rotarymovement in the bore serves the added ofiice of sealing the barrelagainst passage of moisture therefrom into the tobacco bowl. It will beunderstood by reason, principally, of the metallic nature of the barrelthat there is an appreciable deposit of coal tars and the like from thesmoke, the metal promoting the condensation processes, and that theclosure elements must therefore be frequently removed for cleaning thebarrel. Stating the same generally, the objects of the invention are toso engineer a pipe of the character described that the closure elements,namely the plug-valve and the mouth-piece, may be readily removed fromtheir respective seat and wherein each of these closure parts, whenapplied to the barrel, is assured a leakproof fit relative to the seat.

Further and more particular objects and advantages of the invention willappear in the course of the following description and claims, theinvention consisting in the novel construction and in the adaptation andcombination of parts hereinafter described and claimed.

In the drawing:

Figure l is a fragmentary longitudinal vertical section representing,appreciably enlarged from a true scale, a pipe assembly of barrel, bowland plug-valve embodying the present improvements.

Fig. 2 is a transverse vertical section on line 22 of Fig. 1; and

Fig. 3 is a diagrammatic View indicating salient angularities whichcharacterize the plug-valve and its seat, there being considerablediscrepancy between the indicated and the executed angles in orderthereby to clarify the illustration.

The barrel of the pipe is denoted by the numeral 5 and is or may be ofDuralumin or other light-weight metal relatively high in heatconductivity having a throughbore 6 which is cylindrical excepting forthe two ends which are flared. In the upper wall of the barrel proximateto but spaced rearwardly from the forward flare is a port 1 by whichsmoke is drawn into the bore from a tobacco-receiving bowl 8, theattachment of this bowl being desirably accomplished by prolonging theport upwardly through an upstanding and internally-threaded neck 9 overwhich the bowl seats, and threading into the neck a headed center-boredmetallic screw I!) which finds bearing engagement against the floor ofthe bowl. Into the rear end of the bore is fitted a removablemouth-piece (not shown) and in the forward end is fitted a removableplug-valve II. The present invention relates primarily to the plug-valveand its seat but it will be obvious that some of the details ofconstruction of the plugvalve and its seat are as well applicable to themouth-piece and its seat, and to the extent of this applicability myintention is to include one by reference to the other.

Referring therefore to the plug-valve, and describing first the seattherefor, it will be seen from an inspection of Fig.3 that theflarewhich characterizes the forward end of the bore is produced to anangularity of 5 from the axial line of the bore, and that there isprovided between this end flare and the cylindrical bore proper of thebarrel a 3 flare.

The plug itself is desirably metallic and is in the nature of a thimblehaving a knurled head l2 and a tubular neck [3. The neck, consideringits external surface, is produced at the two ends, which is to sayproximate to and remote from the head, with cylindrical parts [4 and I5and between the cylindrical parts has a tapering part It which isarranged to seat against and therefore generally corresponds inangularity and length to the end flare of the barrel. Said cylindricalpart [4 is formed to a diameter somewhat reduced from the diameter whichobtains at the outer limit of th end flare, and the cylindrical part l5,being the part remote from the head, closely fits the body proper of thebore and in the seated position of the plug projects into the borebeyond the rear limit of the smoke port 1. I! denotes a port provided inthe wall of the plug in a position whereat, by rotation of the plug; theport is brought into and out of register with the port I, and it will benoted that such port I! is of a sufiicient diameter and so located inrelation to the center-bore of the screw ID as to permit the plug towear-in to a degree commensurable with the cylindrical part l4 withoutinterrupting a free travel of the smoke into the barrel. Otherwisestated, the port I! and the center-bore of the screw III are so related,one to the other and to the length of the cylindrical part M, as tomaintain throughout the life of the valve an uninterrupted flow of smokefrom the feed conduit into the barrel.

While the 3 flare of the barrel wall functions in effect to round theshoulder which would otherwise occur at the point of juncture betweenthe cylindrical and the 5 surfaces, this important end may be augmentedor, in point of fact, an equivalent end accomplished by grooving theplug circumferentially at the point of juncture of the cylindrical andtapering parts 15 and I6, respectively, affording thereby what may beconsidered a reverse fillet l8. While the delineating edges of thisgroove are barely discernible in actual practice the showing isexaggerated in the drawing to difierentiate the groove from theadjoining surfaces.

Generalizing somewhat, I have found that a proper seating dependsprimarily upon the elimination of wear in a spot sense, as distinguishedfrom a wearing action distributed over an extended area. This I haveaccomplished by deleting abrupt shoulders between adjoining faces. Suchremoval of the shouldering edges is also of very major import in that itholds a pocket of air between the plug and its seat to prevent the plugfrom becoming frozen in the barrel. The flare. of the seat, which is tosay the 5 angle, I

consider relatively critical to the operating efficiency of the plug.

What I claim is:

1. In a smoking device, in combination: a barrel member formed with asmoke chamber therein and having a bore leading to said chamber andfunctioning as a seat for the reception of a removable plug-valve, saidbore being substantially cylindrical at its inner end and having atapered part at its outer end and, in the wall of said cylindrical part,providing a port for the admission of smoke to the chamber of thebarrel; and a removable plug-valve arranged to seat in said bore, havingits inner and outer parts produced to angularities corresponding withthe inner cylindrical and the outer tapered parts of the seat and,between said inner cylindrical and outer tapered parts, beingcircumferentially grooved to provide a reverse fillet functioning in theseated position of the valve to lap the point describing a meeting ofthe plane of the inner cylindrical part of the bore with the plane ofthe outer tapered part of the bore, said inner cylindrical partproviding means acting by rotation of the seated valve to open and closethe smoke port in relation to the chamber.

2. In a smoking device, in combination: a barrel member formed withsmoke chamber therein and having a bore leading to said chamber andfunctioning as a seat for the reception of a removable plug-valve, saidbore being substantially cylindrical at its inner end, having a taperedpart at its outer end and, between and merging with said inner and outercylindrical and tapered parts, being provided with a central taperedpart of an angularity less than that of the outer taper, the wall ofsaid cylindrical part being ported for the admission of smoke to thechamber of the barrel; and a removable plugvalve arranged to seat insaid bore, having its inner and outer parts produced to relativeangularities corresponding with that of the inner cylindrical and theouter tapered parts of the seat and characterized as to length in that,when seated within the bore, the tapered surface of the valve extendsinwardly beyond the point of juncture of the outer taper with thecentral taper of the bore, and the cylindrical surface of the valveextends in the opposite direction beyond the point of juncture of saidcentral tapered part with the inner cylndrical part of the bore, saidcylindrical part of the valve having means acting by rotation of theseated valve to open and close the smoke port in relation to thechamber.

KURT F. J. KIRSTEN.

